To maintain a healthy body, you should exercise on a daily basis. If you want another specific reason to start exercising or increase your frequency of exercise, it’s your HDL levels. Increased physical activity directly helps raise your HDL cholesterol — just another one of the many benefits of exercise. Vigorous exercise is the best choice for boosting HDL, but any additional exercise is better than none. (2)

As you already know, HDL is considered the good guy in the cholesterol game, and it can help your liver to get rid of the unhelpful cholesterol in your body. This is a very important task that HDL is able to accomplish since cholesterol can’t simply dissolve into the blood. The liver has the job of processing cholesterol among its other important jobs. HDL is the liver’s helper and a very good one at that. Having high levels of HDL reduces your risk for both heart disease and stroke, which is why you want to get your cholesterol under control. (10)

In a Canadian study, drinking a few glasses of orange juice every day for four weeks increased participants’ HDL by 21 percent, possibly due to a flavonoid called hesperidin that appears extremely HDL-friendly. Subsequent research found that tangerine juice may be even more effective. Unfortunately, that much juice will add hundreds of excess sugar calories to your diet. So stick to a glass a day and be satisfied with lesser results. Or you can buy hesperidin as a supplement, though it won’t replace the many beneficial nutrients of orange juice (and certainly won’t taste as good).
According to a study published in November 2015 in the journal Nature, a diet high in carbohydrates — like added sugar, white bread, cookies, and cakes — reduces HDL cholesterol levels, increasing the risk for metabolic disorders. Refined carbohydrates found in foods labeled “low-fat” make these just as bad as full-fat foods because the fat is often replaced with carbohydrates from added sugar and other starches.
You've probably heard that fried foods of all kinds, hydrogenated oils, and full-fat dairy products are cholesterol bombs that are best avoided (and not just by those watching their cholesterol levels). The American Heart Association recommends that everyone restrict these foods, as they contain trans and saturated fats, the "bad" kind that raises LDL cholesterol and leads to plaque buildup in the arteries.